作者:Hin-Hee Kim、Sang-Pil Han、Jeong-Kwon Kim、Yeong-Joon Kim
DOI:10.5012/bkcs.2011.32.3.915
日期:2011.3.20
Four esters of succinic and maleic acid were synthesized, separated by thin-layer chromatography (TLC), and identified using matrix-assisted laser desorption/ionization-mass spectrometry (MALDI-MS). A comparison of matrix materials showed that 2,6-dihydroxybenzoic acid (2,6-DHB) yielded a greater ionization efficiency than 2,5-DHB prior to TLC separation. The location of each ester sample on the TLC plate was estimated by comparing the developed plate with a duplicate plate that had been visualized by immersion in a $KMnO_4$ solution. Generally, mass spectra obtained from the $KMnO_4$-visualized plate were relatively poor. Reproducible mass spectra with high peak abundance were difficult to obtain using the 2,6-DHB matrix from crude synthetic esters extracted from the TLC plates. Significant improvements in both reproducibility and sensitivity were realized by using pencil lead as the MALDI matrix. The current methodology will be beneficial to organic chemists since it can provide a guideline for simple and rapid characterization of small organic compounds.
琥珀酸和马来酸的四种酯被合成、通过薄层色谱法(TLC)分离,并使用基质辅助激光解吸电离质谱法(MALDI-MS)进行鉴定。对基质材料的比较表明,在TLC分离之前,2,6-二羟基苯甲酸(2,6-DHB)的电离效率高于2,5-DHB。通过将展开的TLC板与浸入高锰酸钾溶液后可视化的复制板进行比较,估算了每个酯样品在TLC板上的位置。通常,从高锰酸钾可视化的板上获得的质谱相对较差。使用2,6-DHB基质从TLC板上提取的粗合成酯中难以获得具有高丰度峰的可重复质谱。通过使用铅笔芯作为MALDI基质,显著提高了重复性和灵敏度。当前方法将有利于有机化学家,因为它可以为简单快速地表征小有机化合物提供指导。